Photographic camera lens and diaphragm-mounting mechanism

ABSTRACT

A lens and diaphragm mounting barrel mechanism for a photographic camera. The mechanism comprises a fixed barrel and a rotatable barrel interconnected by helicoid structures to cause relative axial movement of the rotatable barrel in response to rotation thereof. A diaphragm is mounted within the rotatable barrel and is interconnected with the fixed barrel to prevent its rotation relative to the latter.

United States Patent Kobayashi et al. Feb. 22, 1972 [54] PHOTOGRAPHICCAMERA LENS AND [56] References Cited DIAPHRAGM-MOUNTING MECHANISMUNITED STATES PATENTS [72] Inventors: Tatsuo Kobayashl, Kaizuka; Keisuke2 966 105 l2/l960 S chutz ..95/64 B m? Osaka Kym Uesugii Saka" 3,489,0711/1970 Mohr et al ..95/64 B 731 Assignee: Minolta Camera KabushlkiKaisha, Osaka, FOREIGN PATENTS OR APPLICATIONS Japan 44/2538 2/l969Japan ..95/64 8 [22] Filed: Feb. 9 [970 778,209 7/1957 Great Britain..95/64 B PP 9,717 Primary Examiner-Joseph F. Peters, Jr.

- ArrameyWatson, Cole, Grindle and Watson [57] ABSTRACT [30] FomgnApphcamm Pflomy Data A lens and diaphragm mounting barrel mechanism fora Feb. I8, 1969 Japan ..44/ 12094 photographic camera. The mechanismcomprises a fixed bar- Mar. 19, 1969 Japan ..44/21049 rel and arotatable barrel interconnected by helicoid structures to cause relativeaxial movement of the rotatable barrel [52] U.S.Cl ..95/64 B, 95/42 inresponse to rotation thereof. A diaphragm is mounted [51] Int. Cl.within the rotatable barrel and is interconnected with the fixed [58]Field of Search ..95/64 R, 64 B, 44 R, 42 barrel to prevent its rotationrelative to the latter.

3 Claims, 5 Drawing Figures PAIENIE0FEB22 m2 3, 643 578 SHEET10F3 FIG. I

I6 72III5B41 INVENTOR BY V? ATTORNEY PHOTOGRAPIIIC CAMERA LENS ANDDIAPHRAGM- MOUNTING MECHANISM BACKGROUND OF THE INVENTION Except forfixed focal point type cameras, distance adjustment in ordinary camerasis accomplished by moving the lenses longitudinally of the optical axisof the camera, and the diaphragm is generally supported in the lensbarrel to insure proper exposure conditions.

There are three known structures for accomplishing movement of the lensbarrel: (1) combination of a double helicoid and a beeline key; (2) setof helicoids, a set of rotatable fitting portions and a beeline key; and(3) a rotary means comprising a set of helicoids for axially moving thelens barrel in response to rotation thereof. The former two structureshave many parts, and the construction thereof complicated iscomplicated. Accordingly rotary means are preferable.

It is preferred that the operating means for the diaphragm device belocated on the camera body or on the side of the fixed lens barrel inorder to facilitate adjustment of the diaphragm. Further, it would bedesirable to be able to preset the diaphragm value and yet be able toadjust the image and the exposure with the diaphragm in its full openstate, the diaphragm being stopped down to its preset value inconnection with the shutter release operation. None of cameras the priorart have included all of these desirable features.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide a lens and diaphragm mounting device which permits diaphragmmanipulation to be carried out by means of a diaphragm-adjusting devicedisposed on the camera body side or the fixed barrel of a camera havingthe rotary lens-adjusting means.

A second object of the present invention is to provide such a mountingdevice wherein the diaphragm is incorporated in the lens system in abarrel movable in the optical axis direction the diaphragm being fixedin a regular position relative to the photosensitive surface tostandardize the distance between the diaphragm device and the filmsurface regardless of movement of the lens system in the optical axisdirection.

Another object of the present invention is to permit the adjustment andcontrol of the diaphragm device to be carried out from the camera bodyside or the fixed barrel in a camera having rotary adjustment means andwherein the diaphragm device is movable in the optical axis directiontogether with the rotatable barrel and yet at the same time is supportedagainst rotation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a longitudinal section of alens and diaphragm mounting mechanism constructed in accordance with thepresent invention.

FIG. 2 is an enlarged cross-sectional view taken along line A-A in FIG.I.

FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1.

FIG. 4 is a longitudinal view of another form of mechanism constructedin accordance with the present invention.

FIG. 5 is a perspective, exploded view showing the diaphragm device, therotation check member and the diaphragm control member of the embodimentshown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the first embodiment inaccordance with the present invention shown in FIGS. 1, 2 and 3, thediaphragm device is located in the barrel movable in the optical axisdirection and is supported against movement in either the rotarydirection or along the optical axis.

Rotary delivery type lens barrel 7 is composed of male helicoid tube 7,having a male helicoid 7, on its outer surface,

front lens holding portion 7., fixed on the front end of said malehelicoid tube 7,, rear plate 7;, fixed to the rear end of said malehelicoid tube 7 and rear lens holding portion 7,, fixed to said rearplate 7 Lenses 1, 2, 3, 4, 5 and 6 form a lens system held by saidlens-holding portions 7,, 7 and present lens space 1 between lenses 3and 4 in which a diaphragm device having diaphragm blades 20 isinterposed space 1 is slightly larger than the moving distance along theoptical axis direction in which said lens barrel 7 is moved from theinfinite to a very short photographing distance.

Onto the periphery of the front end of male helicoid 7-, of said lensbarrel 7 are fixed distance ring 8 and stopper ring 9, and said stopperring 9 is extended having a clearance above male helicoid tube 7 andnotch portion 9, is formed thereon as shown in FIG. 2. The depth of saidnotch 9 is a little longer than the distance of movement of the lensbarrel from the infinite photographing to very short distancephotographing, and the length of the arch surface width of said notchportion 9, which meets at right angles with said depth is formedequivalently to the angle through which lens barrel 7 rotates when saidmovement is effected.

Outer tube 12 is fixed to barrel baseplate 11 which has a bayonet orscrew fitting portion 10 facilitating attachment to the camera body. Afemale helicoid tube I3 is fixed onto tube 12 through adjusting membersl4, 15 to mesh with male helicoid 7, of helicoid tube 7 of said lensbarrel 7, and the front end of said female helicoid tube 13 is insertedinto the clearance between male helicoid tube 7 stopper ring 6. A pin 16mounted on the periphery of the front end of said female helicoid tube13 projects into notch portion 9, provided on said stop ring 9. Whenlens barrel 7 is in the infinite photographing distance said pin 16 isin the deepest position on the right side edge of notch portion 9, asshown in FIG. 2 and when said lens barrel 7 comes to the very shortphotographing distance said pin 16 engages with the shallow position onthe left side edge of notch 9, to check the further rotation of lensbarrel 7.

On barrel base plate 11 there are mounted three struts 17,, 17 17 forholding the diaphragm device and as shown in FIG. 3 said struts 17,, I717,, pass through three arcuated slots 18,, 18 18,, provided on rearplate 7,, of lens barrel tube 7. Therefore, the arcuated length of saidslots should be equivalent to the rotary angle through which lens barreltube 7 is adjusted.

To the ends of struts 17,, 17 17 there is fixed diaphragm blade case 19of the diaphragm device, on which diaphragm blades 20, blade controlplate 21, and blade keep plate 22 for forming the well-known diaphragmdevice are provided.

A diaphragm adjustment ring 23 is rotatably mounted on the rear portionon the periphery of outer tube 12 and the diaphragm is preset by indexesgraduated on the periphery of outer tube 12 and diaphragm scalesgraduated on diaphragm ring 23 as is well known. Control portion 23, ofsaid diaphragm setup ring 23 passes through long slot 12, provided onouter tube 12 and projects into the inside of said outer tube. Lever 24for control portion 23, is rotatable using strut 17,, as a center and isformed to work so as not to come into contact with struts 17 Bentportion 24, of said setup lever 24 passes through arcuated slot 18;, toproject into the inside of lens barrel 7 and engages with setup pin 28which projects through slot 19, provided on diaphragm blade case 19 fromblade control 21 of the diaphragm device.

Bent portion 27, of working lever 27 engages with working pin 29 whichprojects through another slot I9 provided on diaphragm blade case I9 andprojects rearward through another arcuated slot 18, provided on bottomplate 7;, of lens barrel tube 7. Working lever 27 is supported rotatablyalong rear plate 7;, using strut 17, as a center, and auto-presetdiaphragm pin 26 projected from said working lever 27 engages withdriving lever 25 for working in interlocking connection with the shutterrelease operation not shown in the drawings. 1

Reference numeral 30 shown by a broken line denotes a photosensitivefilm surface.

In said first embodiment, the diaphragm device is fixed so as not torotate together'with lens barrel tube 7 and also not to move in theoptical axis direction. Therefore, in order to interpose the diaphragmdevice in the lens system, as described above any lens space I isrequired to be larger than the moving distance in the optical axisdirection of the lens barrel tube. However, the diaphragm device is inan immovable position to photosensitive film surface 30 shown in FIG. 1.When focusing is in the infinite the diaphragm device comes near to lens3 and when focusing is in the short distance the diaphragm device comesnear to lens 4. For example, therefore, when the lens system is formedof Gaussian-type lenses, in general the effective diameter of light rayscoming to the front of the rear lens group will be smaller than thosecoming from the rear of the front lens group, therefore, the F number ofthe lens is variable in accordance with the photographing distance.However, according to the present invention, compensating therefor ispossible.

In the second embodiment in accordance with the present invention shownin FIG. 4 and FIG. 5, the diaphragm device is movable in the opticalaxis direction together with the lens barrel and is supported so as tocheck rotation, and yet it is possible to manipulate or control thediaphragm device from the camera body side or the fixed barrel side.

Lens barrel 107 for bearing the lens system is composed of male helicoidportion 102 presenting male helicoid 101 on its periphery, rear plate103 for said male helicoid portion 102, the rearle'ns holding portion104 connected thereto, the front lens holding portion 105 connected tothe front end of the male helicoid portion, collar 106 projecting inwardfrom male helicoid portion 102 between lens-holding portions 014 and105, annular slot 119 formed in the inside right behind said collar 106,distance ring 108 formed on the front peripheryof male helicoid portion102, and cover tube 109 extending rear ward from said distance ring 108with clearance left between male helicoid portion 102 and said covertube 109.

On the central portion of baseplate 111 of fixed barrel 112 where afitting 110 for connecting the devices to the camera body is provided, ahole 115 is provided for receiving rear lens-holding portion 105 of lensbarrel 107 therethrough. Female helicoid portion 113 extends forward offixed barrel 112 and presents female helicoid. 114 which is formed so asto engage with male helicoid 101 of said lens barrel 107. On the rearend on the periphery of fixed barrel 112 a diaphragm setup ring 116 isrotatably mounted, and setup cam 117 thereof passes through slot 118provided on fixed barrel 112 to project into the inside thereof.

As for the diaphragm device, as shown clearly in FIG. 5, an-

' nular disk 123 is provided with slots 124 which extend in the radialdirection and in which one of pins 121 provided on diaphragm blade 120is fitted. Disc 123 is fitted rotatably in annular slot 119 providedinside said male helicoid portion 102 on its periphery and holdsdiaphragm blades 120 between collar 106 and said annular disk 123.

Said annular disk 123 has holding pin 125 mounted thereon to projectrearward and disc 123 rotatably supports diaphragm control plate 126concentrically in the inside thereof. Into a small hole 127 provided onsaid diaphragm control plate 126 another pin 122 provided on each ofsaid diaphragm blades 120 is fitted to open or close said diaphragmblades 120 through relative rotation of annular disk 123 and diaphragmcontrol plate 126.

On fitting portion 128 which is mounted fixedly on the back of diaphragmcontrol plate 126, a control pin 129 is mounted to project rearward topass through arcuated slot 130 provided on rearplate 103 of lens barrel107 and fit slidably in the optical axis direction into fork portion 133formed on the inside edge of C-shaped arch lever- 131 which is connectedrotatably in pin hole 132 to a pin (not shown in the drawings) providedinside baseplate 111 of fixed barrel 112. And. in the same way holdingpin mounted on annular disk 123 also passes through another arcuate slotprovided on rear plate 103 of lens barrel 107 to project rearward andfit slidably in the optical axis direction into fork portion 139provided on holding plate 138 fixed to the inside of fixed barrel 112.

Automatic diaphragm interlocking pin 134 mounted on the back of saidarch lever 131 passes through arch slot 137 provided on baseplate 111 offixed barrel 112 and projects rear ward to engage with the side marginof working lever 140. Said working lever 140 is mounted on the camerabody and is movable in the direction shown by arrow 141 at the beginningof release operation. Pins 134 and lever 150 are pressed into contactwith each other by means of spring provided on arch lever 131. Movementof said working lever in the direction shown by said arrow 141 causesarch lever 131 to rotate counterclockwise in P16. 5 to operate so as torotate plate 126 through working pin 129.

On said arch lever 131 there is mounted apin 136 which 7 cooperates withsetup cam 117 mounted on diaphragm setup ring 116 to restrict thecounterclockwise rotation of arch lever 131 to bring diaphragm blades120 to a preset diaphragm value.

In this embodiment, even though lens barrel 107 is rotated duringfocusing the diaphragm device in the lens barrel is held againstrotation by the cooperation between holding pin 125 and holding plate138, which is fixed, on fixed barrel 112. Annular disk 123 merelyslidesin contact with annular slot 119.

To permit movement of lens barrel 107 inthe optical axis direction,holding pin 125 slides in fork portion 139 of holding plate 138 andtherefore the diaphragm device may move in the optical directiontogether with the lens barrel to retain its normal position relative tothe lens system.

We claim:

1. A lens and diaphragm mounting barrel mechanism for a photographiccamera comprising:

a fixed barrel;

a lens barrel, said barrels being coaxially aligned and each beingprovided with mating, interengaged helicoid structures whereby relativerotation of the barrels cause relative axial movement thereof;

a set of lenses mounted coaxially within said lens barrel;

a diaphragm structure disposed within the lens barrel in coaxialalignment with said lenses, said structure comprising a pair of ringsrelatively rotatable to adjust the opening of the diaphragm,

said lens barrel having an end plate disposed transversely of the commonaxis of the barrels, there being an arcuate slot in said plate disposedto extend generally circumferentially of the axis of said barrels;

linkage interconnecting one of said rings and said fixed barrel forpreventing relative rotation therebetween about said axis, said linkageincluding a member extending longitudinally of the axis and through saidarcuate slot; and

automatic diaphragm-operating means coupled with the other of said ringsfor positioning the latter to correspond to a predetermined diaphragmopening in response to actuation of the shutter release of the camera.

2. Barrel mechanism as'set forth in claim 1 wherein said diaphragm ismounted in said lens barrel for axial movement therewith and forrotation relative thereto-about said axis, said fixed barrel includedmeans defining an axially extending hole slidably receiving said membertherein. I

3. Barrel mechanism as set forth in claim 1 wherein said diaphragm issupported against axial movement relative to said fixed barrel by saidmember and said lens barrel is axially movable relative thereto.

1. A lens and diaphragm mounting barrel mechanism for a photographiccamera comprising: a fixed barrel; a lens barrel, said barrels beingcoaxially aligned and each being provided with mating, interengagedhelicoid structures whereby relative rotation of the barrels causerelative axial movement thereof; a set of lenses mounted coaxiallywithin said lens barrel; a diaphragm structure disposed within the lensbarrel in coaxial alignment with said lenses, said structure comprisinga pair of rings relatively rotatable to adjust the opening of thediaphragm, said lens barrel having an end plate disposed transversely ofthe common axis of the barrels, there being an arcuate slot in saidplate disposed to extend generally circumferentially of the axis of saidbarrels; linkage interconnecting one of said rings and said fixed barrelfor preventIng relative rotation therebetween about said axis, saidlinkage including a member extending longitudinally of the axis andthrough said arcuate slot; and automatic diaphragm-operating meanscoupled with the other of said rings for positioning the latter tocorrespond to a predetermined diaphragm opening in response to actuationof the shutter release of the camera.
 2. Barrel mechanism as set forthin claim 1 wherein said diaphragm is mounted in said lens barrel foraxial movement therewith and for rotation relative thereto about saidaxis, said fixed barrel included means defining an axially extendinghole slidably receiving said member therein.
 3. Barrel mechanism as setforth in claim 1 wherein said diaphragm is supported against axialmovement relative to said fixed barrel by said member and said lensbarrel is axially movable relative thereto.